Trouble Codes 133 153

[gman75]

I have worked with hp tuners for quite a while now and know the ins and outs for the basics but i have the two trouble codes listed. They keep re occuring and i am not sure what the problem is anymore. I have had the car dyno tuned by a reputable guy who addressed this problem and checked to see if it was the wiring and he ruled out that possibilty. i have replaced the O2 extentions and the O2 sensors in the front, the rears have simms in them. i have heard that it can be from an exhuast leak upstream from the O2 sensor which would for me mean the exhuast port attachment site. the A.I.R. system has been welded shut so that shouldn't be the case. the headers have new gaskets on them and i used RTV sealent to help ensure the seal. i also torqued the bolts to specs and retorqued them after a few hours of run time to adjust for the movement during heating. I would take the car back to the tuner and say deal with it but right now i am in college and when i go home it is not something i want to deal with driving another distance to take care of.

Thanks,
Garrett

[rattle]

heres what gm says about those codes

DTC P0133 or P0153
Circuit Description
The powertrain control module (PCM) continuously monitors the heated oxygen sensor (HO2S) activity for 100 seconds. During the monitor period the PCM counts the number of times that the HO2S responds from rich to lean and from lean to rich, and adds the amount of time that was needed to complete all transitions. With this information, the PCM can determine the average time for all transitions. If the average response time is too slow, a DTC will set.

The PCM determines the lean to rich transition when the HO2S voltage changes from less than 300 mV to more than 600 mV. The PCM determines the rich to lean transition when the HO2S voltage changes from more than 600 mV to less than 300 mV. An HO2S that responds too slowly is most likely defective

So now what you have to do is log some data, are your o2s pegging low, pegging high, or just lazy (too cold), if lazy you could put some catalyst monitor o2s into the engine monitor location (hotter heater elements), or use header wrap to maintain more heat, that is about it for mechanical fixes.

onto the tuner fixes, you get to learn how to adjust your o2 sensor error closed loop proportional gain values to achieve nice active sensor readings again. basically when you look at the table, for a given mv error use the given multiplier to force ocillation. you will notice the bigger the o2 error the bigger the multiplier, so for example if your o2 pegged at 60 mv and the multiplier is 4.00, you may need to increase the lean cell in the table under the 420MV error line. if it was pegged rich you adjust the rich line

OR

just go into Engine Diagnostics, and set those two codes to No Mil or No Error reporting

[arthansen]

The Sims are not working. I had the same problem and they sent me three different sims until we found one that worked. Of course, a month later I got HP Tuners, took out the sim and deleted the codes. Just set all codes that say Bank 1 or 2, sensor 2 to No error reporting and SES enabled Off. Good Luck.

[gman75]

Thanks for the directional help. To rattle i remember reading somewhere that the codes could also mean an exhuast leak up stream and i have turned off the codes before through hptuners but it was still setting off the light and code even after i took off the light and the error report. I have yet to try altering the table but i am not 100% clear how that would work if you could give me detailed instructions on it and why it will help that would be appreciated.
To arthanson, thanks but the simms on the car right now have always worked and i eliminated the sensors with hp tuners anyway so it shouldn't be the rear sensors that go into the catalytic converters.

Thanks,
Garrett

[arthansen]

My bad. P0133 and P0152 are both Sensor 1 codes, not the Sensor 2 (rear). Sorry about that. Was going from memory and I guess my memory is going. ;D

[rattle]

if you have exhaust leaks that will definately affect your o2 readings

if you dont have exhaust leaks and you know your sensors are good and you have already tried the rear sensors (with hotter heaters) in the front position and you dont want to put header wrap on to keep the heat in your pipes which will keep your o2s warm enough to operate correctly then you can mess with the 02 error tables.

the tables basically tell the pcm how much to adjust the fuel by for a given amount of o2 error, if the error is small it wont take much adjustment to push afr the other way,

first look at your closed loop proportional gain vs o2 error.

see you have two lines, lean and rich, and mv error columns, 0mv......420mv

the mv values represent how far away from 451mv (or whatever value is set in the o2 rich/lean vs airflow table. the actual values in the table are multipliers used to adjust the fuel ratio to keep the o2s swinging back and forth, now if your o2s are cold due to header they will be reading slow so you will need to increase the multiplier to induce some overshoot that the cold sensor can actually see, dont go too far or you will get a surge condition. Its going to be hit and miss, trial and error and marginally acceptable at best,

just wrap the headers, at least the bottom half that you cant see from under the hood, or better yet get the headers porcelain coated.

[gman75]

Your input has been beneficial so far and as far as coating the headers they are jet hot coated. So i should just wrap the headers on the underside of the car and see if that helps and then if it doesn't work go to plan B and alter the tables? Or should i just take it down to the guy who tuned it and say you get to deal with it? the only problem with that is i don't live to close to him right now but if that is what needs to be done they i guess over christmas i will do it. what are the chances it is an acutal exhuast leak. i have heard that people reuse the manifold gaskets from the old maifolds becuase of leakage problems should i break down and put those gaskets on. i used the ones from Jet Hot which are just regular old rubber and used RTV sealant to try and assure that they would seal to the head. i used gaskets like that on my boat which has a 350 inboard and it is pushing water through them and they sealed fine to the head.

Thanks
Garrett

[rattle]

for header gaskets i like to use the multi layer tin gaskets that were used on the 5.7 vortec engines, you can easily port match them to work on most engines, i coat them with ultracopper (very thinly).

You can easily check for exhaust leaks with the help of a friend, let the engine idle and have someone restrict NOT plug the tailpipes while you listen for pressure leaks. This is all made much easier with a cheap stethoscope or very expensive ultrasonic leak detector.

[gman75]

I will try that. here is some new info, i went out on the highway and didn't log which was stupid of me and i could just upload the file but i watched to o2 sensor mv and they were all over the place from like 100-700 up and down a lot is that suppose to happen or are they suppose to be somewhat steady? hopefully that helps to make some headway to the problem. i am going to order header wrap and insulate the headers to try and increase temp to help but i just thought that info would lead to one direction on the answer.

Thanks,
Garrett